I need to post this to get it out of my system and to find out what the hell is happening.

I am modding GTAIV, just simple vehicle stuff like speed and weight. I use the magicIV patch and go on, im not setting anything to silly values and my game with randomly break, eg. I set the sultan RS speed to 350 and it works fine, but if i go back and change another car's speed to somthing similar, it will break and not lauch! but the worst thing is backups DONT WORK and its stressing me out so much, if re-installed gta about 11 times in total so far.ASnd if your gonna reply by telling me not to mod the game, tough the only reason i got this game for PC was the modding. please someone help me as its really really really getting to me because its not like a quick install, it takes so long to install and starting everything again, so far iv had it almost perfect twice. the second time wwas about 10 minutes ago. backups just wont work atall I need to know what the hell I am doing wrong!

Thanks I will give that a try when its finished installing, and dont worry about the service pack I dont want you to go right out your way to help me XD GTAIV install is half done installing, i started installing just before making the first post.